A number of devices and fasteners are currently available for fastening panels, such as body panels and automobile interior trim piece panels, to the chassis of a vehicle. As used herein, a body panel refers to, for example, any interior or exterior body panel on a vehicle, a plastic interior trim piece, headliner or any interior trim piece. Additionally, the panel may be any suitable exterior body panel, such as a fender, bumper, quarter panel or door panel. The chassis of the vehicle may include any substrate, plate, body panel, structural framework, chassis component or subcomponent, wall or any suitable object.
These body panels typically are required to attach to the chassis of an automobile with a relatively low level of insertion force while providing a high level of extraction force suitable to maintain attachment of the panel to the chassis. However, these conventional fastener devices instead provide approximately relatively equal levels of insertion and extraction force. Further, conventional fasteners typically do not adequately secure the panel to the vehicle chassis having sheet metal with different curvature or thicknesses throughout. Also, conventional fasteners are not suitable under a variety of environmental conditions, such as in the presence of vibration at various levels of amplitude and frequency. For example, the fastener device should prevent or minimize the amount of buzzing, rattling or any other type of noise that may cause attention to the occupants of the vehicle or otherwise weaken the attachment. Also, conventional fasteners do not adequately accommodate various levels of production tolerances, such as various dimensions amongst, for example, the body panels as well as the vehicle chassis. Thus, conventional fastener devices typically do not adequately fasten to a range of sheet metal thicknesses and do not minimize or eliminate buzzing and rattling and do not sufficiently accommodate variations in production tolerances.
Fastener clips, such as metal spring fasteners, are known for attaching body panels to an automobile chassis. For example, fastener clips are known having a base plate and four stepped arms extending from the base plate. Each stepped arm includes four incremental steps (stair-steps) suitable for engaging a slot in a vehicle chassis with one of the steps on each arm. The incremental steps allow for engagement, however, in only one of the four discrete step positions rather than over a continuous range of engagement positions. Further, each step has a relatively large rise and run so that, once inserted, movement of the fastener clip within the range of a step size may occur, resulting in wear and/or the generation of noise, including buzzing and rattling as a result of vibrations occurring within the vehicle. Also, the steps typically cut onto each arm during manufacture and also require twisting of each wing on the fastener clip in order to engage the slot in the vehicle chassis. As a result, only an edge or a portion of an edge of each of the steps engages the hole in the vehicle slot.
If the sheet metal varies in thickness or if tolerances in production of the slot in the vehicle chassis or in the trim-piece exist, for example, then engagement of one portion of the hole in the chassis with one of the arms may not provide suitable frictional engagement or otherwise result in movement. Further, less than all four of the arms will make engagement with the slot of the vehicle chassis. Twisting of the body panel will be likely more prevalent because less than four contact points are actually made with the slot of the vehicle chassis. As a result, wear, squeaks, rattles, buzzing, corrosion and loss of elasticity and loss of sealing may result, especially after years of vehicle operation and exposure to vibration and other environmental conditions.